US20190118581A1 - Pneumatic Tire - Google Patents
Pneumatic Tire Download PDFInfo
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- US20190118581A1 US20190118581A1 US16/091,506 US201716091506A US2019118581A1 US 20190118581 A1 US20190118581 A1 US 20190118581A1 US 201716091506 A US201716091506 A US 201716091506A US 2019118581 A1 US2019118581 A1 US 2019118581A1
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- narrow groove
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- 238000012360 testing method Methods 0.000 description 13
- 230000000694 effects Effects 0.000 description 12
- 238000005516 engineering process Methods 0.000 description 9
- 238000011156 evaluation Methods 0.000 description 8
- 238000011056 performance test Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000001154 acute effect Effects 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/0302—Tread patterns directional pattern, i.e. with main rolling direction
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/0306—Patterns comprising block rows or discontinuous ribs
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1236—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1259—Depth of the sipe
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/13—Tread patterns characterised by the groove cross-section, e.g. for buttressing or preventing stone-trapping
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/11—Tread patterns in which the raised area of the pattern consists only of isolated elements, e.g. blocks
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0341—Circumferential grooves
- B60C2011/0346—Circumferential grooves with zigzag shape
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0341—Circumferential grooves
- B60C2011/0348—Narrow grooves, i.e. having a width of less than 4 mm
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0341—Circumferential grooves
- B60C2011/0351—Shallow grooves, i.e. having a depth of less than 50% of other grooves
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0358—Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane
- B60C2011/036—Narrow grooves, i.e. having a width of less than 3 mm
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0358—Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane
- B60C2011/0362—Shallow grooves, i.e. having a depth of less than 50% of other grooves
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C2011/0337—Tread patterns characterised by particular design features of the pattern
- B60C2011/0339—Grooves
- B60C2011/0358—Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane
- B60C2011/0367—Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane characterised by depth
- B60C2011/0369—Lateral grooves, i.e. having an angle of 45 to 90 degees to the equatorial plane characterised by depth with varying depth of the groove
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1204—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe
- B60C2011/1213—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special shape of the sipe sinusoidal or zigzag at the tread surface
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1236—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern
- B60C2011/1245—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes with special arrangements in the tread pattern being arranged in crossing relation, e.g. sipe mesh
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
- B60C11/03—Tread patterns
- B60C11/12—Tread patterns characterised by the use of narrow slits or incisions, e.g. sipes
- B60C11/1259—Depth of the sipe
- B60C2011/1268—Depth of the sipe being different from sipe to sipe
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B60C2200/00—Tyres specially adapted for particular applications
- B60C2200/06—Tyres specially adapted for particular applications for heavy duty vehicles
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
Abstract
Description
- The present technology relates to a pneumatic tire.
- In a pneumatic tire, in order to discharge water between a tread surface and a road surface during running on wet road surfaces, a plurality of grooves are formed in the tread surface. These grooves in the tread surface, however, cause noise when a vehicle runs. Thus, among the pneumatic tires in the related art, there are tires that achieve reduced noise as a result of considerations made to a shape and an arrangement of the grooves. For example, in the pneumatic tire described in Japan Patent No. 5530059, outer longitudinal grooves positioned at or near both ends in a tire lateral direction are formed into zigzag shapes, and positions where the outer longitudinal grooves connect to lateral grooves, which are positioned on both sides of the outer longitudinal grooves in the tire lateral direction and connected to the outer longitudinal grooves from both sides of the outer longitudinal grooves, are made the same in a tire circumferential direction, thereby suppressing noise generation while maintaining wet performance.
- Here, running performance on snow and ice may be required in the pneumatic tire. In such a pneumatic tire, the grooves formed in the tread surface not only include grooves that define blocks but also narrow grooves and the like in the blocks, for example, as in Japan Patent No. 5530059 in which sipes are provided in land portions. Such a configuration effectively increases edges on the tread surface. However, when narrow grooves and the like are provided in the blocks, compressed air flows into the narrow grooves when the blocks contact the ground, readily flowing to main grooves and readily producing noise. Thus, satisfaction of both performance on snow and ice and reduced noise has been extremely difficult.
- The present technology provides a pneumatic tire capable of improving performance on snow and ice and reducing noise in a compatible manner.
- A pneumatic tire according to the present technology includes a tread surface, a plurality of circumferential main grooves formed on the tread surface and extending in a tire circumferential direction, a plurality of lug grooves formed on the tread surface and extending in a tire lateral direction, a plurality of blocks defined by the lug grooves on both sides in the tire circumferential direction and by the circumferential main grooves on at least one end portion in the tire lateral direction, and narrow grooves formed in the blocks. The narrow grooves include a plurality of bent portions as well as a circumferential narrow groove extending in the tire circumferential direction and a lateral narrow groove extending in the tire lateral direction. The lateral narrow groove and the circumferential narrow groove are configured so that at least one thereof is provided in a plurality and includes a plurality of intersection points where the one intersects the other.
- Further, in the pneumatic tire described above, preferably the bent portions are each positioned between the intersection points in the tire lateral direction, the circumferential narrow groove opens to the lug groove, and the lateral narrow groove opens to the circumferential main groove.
- Further, in the pneumatic tire described above, preferably the narrow groove opens to the respective lug grooves defining both sides of the block in the tire circumferential direction, and thus includes two opening portions. A distance W3 in the tire lateral direction between one of the two opening portions and, among both ends of the block in the tire lateral direction, an end portion near the opening portion is within a range of 0.15≤(W3/WB)≤0.40 with respect to a width WB of the block in the tire lateral direction. A distance W4 in the tire lateral direction between the other of the two opening portions and, among both ends of the block in the tire lateral direction, an end portion near the opening portion is within a range of 0.15≤(W4/WB)≤0.40 with respect to the width WB of the block in the tire lateral direction.
- Further, in the pneumatic tire described above, preferably the narrow groove has a groove depth d1 within a range of 0.05≤(d1/d2)≤0.50 with respect to a groove depth d2 of the circumferential main groove.
- Further, in the pneumatic tire described above, preferably the narrow grooves are configured so that a relationship between a groove depth d3 of the circumferential narrow groove and a groove depth d4 of the lateral narrow groove is within a range of 0.5≤(d3/d4)≤0.8.
- Further, in the pneumatic tire described above, preferably the narrow groove includes two of the intersection points, and an angle β1 between the narrow grooves that intersect at one of the intersection points and an angle β2 between the narrow grooves that intersect at the other of the intersection points are within ranges of 70°≤β1≤90° and 70°≤β2≤90°, respectively.
- Further, in the pneumatic tire described above, preferably the narrow groove includes two of the bent portions, and a bend angle α1 of the narrow groove at one of the bent portions and a bend angle α2 of the narrow groove at the other of the bent portions are within ranges of 90°≤α1≤120° and 90°≤α2≤120°, respectively.
- Further, in the pneumatic tire described above, preferably the blocks are configured so that a plurality thereof are aligned in the tire circumferential direction, forming block rows, the tread surface is provided with a plurality of the block rows aligned in the tire lateral direction, and the narrow grooves are formed in the blocks of the plurality of block rows.
- Further, in the pneumatic tire described above, preferably the tread surface is provided with six of the block rows, and the narrow grooves are formed in at least the blocks of four block rows, among the six block rows, other than the two block rows positioned on both end sides in the tire lateral direction.
- Further, in the pneumatic tire described above, preferably the pneumatic tire has a specified rotation direction, and the bent portions bend such that a portion of the narrow groove positioned outward from the bent portion in the tire lateral direction is configured to bend further in directions positioned on a trailing side in a tire rotation direction than a portion of the narrow groove positioned inward from the bent portion in the tire lateral direction.
- A pneumatic tire according to the present technology achieves the effect of improving performance on snow and ice and reducing noise in a compatible manner.
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FIG. 1 is a plan view illustrating a tread surface of a pneumatic tire according to an embodiment. -
FIG. 2 is a detailed view of part A ofFIG. 1 . -
FIG. 3 is a cross-sectional view taken along B-B ofFIG. 2 . -
FIG. 4 is a modified example of the pneumatic tire according to an embodiment, and is an explanatory diagram of a case where bent portions are positioned outward of intersection points. -
FIG. 5 is a modified example of the pneumatic tire according to an embodiment, and is an explanatory diagram of a case where bent portions are formed in circumferential narrow grooves. -
FIG. 6A is a table showing the results of performance tests of pneumatic tires. -
FIG. 6B is a table showing the results of performance tests of pneumatic tires. -
FIG. 6C is a table showing the results of performance tests of pneumatic tires. -
FIG. 6D is a table showing the results of performance tests of pneumatic tires. -
FIG. 6E is a table showing the results of performance tests of pneumatic tires. -
FIG. 6F is a table showing the results of performance tests of pneumatic tires. - Pneumatic tires according to embodiments of the present technology are described in detail below with reference to the drawings. However, the technology is not limited to these embodiments. Constituents of the following embodiments include elements that are essentially identical or that can be substituted or easily conceived by one skilled in the art.
- Herein, “tire lateral direction” refers to the direction that is parallel with a rotation axis of a pneumatic tire. “Inward in the tire lateral direction” refers to the direction toward the tire equatorial plane in the tire lateral direction. “Outward in the tire lateral direction” refers to the direction opposite the direction toward the tire equatorial plane in the tire lateral direction. Further, “tire radial direction” refers to the direction orthogonal to the tire rotation axis. “Tire circumferential direction” refers to the direction of rotation with the tire rotation axis as the center of rotation.
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FIG. 1 is a plan view of a tread surface of a pneumatic tire according to an embodiment. Apneumatic tire 1 illustrated inFIG. 1 is provided with atread portion 2 in an outermost portion in the tire radial direction. The surface of thetread portion 2, i.e., the portion that contacts the road surface when a vehicle (not illustrated) mounted with thepneumatic tire 1 runs, is formed as atread surface 3. A plurality of circumferentialmain grooves 10 extending in the tire circumferential direction and a plurality oflug grooves 15 extending in the tire lateral direction are each formed in thetread portion 3, and a plurality ofblocks 20 serving as land portions are formed by the circumferentialmain grooves 10 and thelug grooves 15. That is, theblocks 20 are defined by thelug grooves 15 on both sides in the tire circumferential direction, and by the circumferentialmain grooves 10 on at least one end portion in the tire lateral direction, and thus each of theblocks 20 has a substantially quadrangular shape. - Specifically, five circumferential
main grooves 10 are formed aligned in the tire lateral direction, each of the five circumferentialmain grooves 10 are formed with repeated bending in the tire lateral direction while extending in the tire circumferential direction. That is, the circumferentialmain grooves 10 extending in the tire circumferential direction are each formed in a zigzag shape. Further, thelug grooves 15 are configured so that thelug grooves 15 that do not penetrate the circumferentialmain grooves 10 and are adjacent to each other via the circumferentialmain grooves 10 are formed in positions that differ in the tire circumferential direction. The circumferentialmain grooves 10 here have a groove width within a range from 3 to 10 mm, both inclusive, and a groove depth within a range from 7 to 25 mm, both inclusive. Further, thelug grooves 15 here have a groove width within a range from 4 to 12 mm, both inclusive, and a groove depth within a range from 5 to 25 mm, both inclusive. - The
blocks 20 defined by the circumferentialmain grooves 10 and thelug grooves 15 are disposed between circumferentialmain grooves 10 adjacent to each other as well as on the outer side in the tire lateral direction of each of the two circumferentialmain grooves 10 positioned most outward in the tire lateral direction. Further, a plurality of theblocks 20 positioned in substantially the same position in the tire lateral direction are aligned in series in the tire circumferential direction via thelug grooves 15, formingblock rows 25 each in a row shape. Such ablock row 25 is formed in four locations between five circumferentialmain grooves 10, and in two locations outward in the tire lateral direction of the two circumferentialmain grooves 10 positioned most outward in the tire lateral direction, forming six rows in total. These sixblock rows 25 are aligned in the tire lateral direction on thetread surface 3. The tread pattern on thetread surface 3 of thepneumatic tire 1 according to the present embodiment is thus a so-called block pattern provided with land portions formed by the plurality ofblocks 20. - Further, the
pneumatic tire 1 according to the present embodiment has a specified rotation direction when mounted on a vehicle. In the description below, a leading side in the tire rotation direction is the rotation direction side when thepneumatic tire 1 rotates in the specified direction and, is the side that first contacts and first separates from the road surface when thepneumatic tire 1 is mounted on a vehicle, rotated in the specified direction, and run. Further, a trailing side in the tire rotation direction is a side opposite to the rotation direction side when thepneumatic tire 1 rotates in the specified direction and, is the side that later contacts and separates from the road surface when thepneumatic tire 1 is mounted on a vehicle, rotated in the specified direction, and run. Each of thelug grooves 15 is inclined in a direction toward the trailing side in the tire rotation direction, as it goes from the tire equator line CL side to an outer side in the tire lateral direction. That is, thelug grooves 15 are each inclined in a direction toward the trailing side in the tire rotation direction, from an inner side toward the outer side in the tire lateral direction while extending in the tire circumferential direction. Note that thelug grooves 15 do not need to be inclined in the tire circumferential direction while extending in the tire lateral direction in all positions in which thelug grooves 15 define theblocks 20 in the tire circumferential direction. At least a portion of thelug grooves 15 that define the leading side of theblocks 20 in the tire rotation direction may be inclined in a direction toward the trailing side in the tire rotation direction, as it goes from the tire equator line CL side toward the outer side in the tire lateral direction. - Further, each of the
blocks 20 of the sixblock rows 25 includenarrow grooves 30. In the four of the sixblock rows 25 other than the two rows outward in the tire lateral direction, thenarrow grooves 30 open to the circumferentialmain grooves 10 and thelug grooves 15 that define each of theblocks 20. Further, in the two of the sixblock rows 25 outward in the tire lateral direction, thenarrow grooves 30 open to the circumferentialmain groove 10 that defines each of theblocks 20 as well as to the outer sides of theblocks 20 in the tire lateral direction. Further, thenarrow grooves 30 are each formed in substantially the same form in each of theblocks 20 of the fourblock rows 25 other than the two rows outward in the tire lateral direction, and in substantially the same form in each of theblocks 20 of the twoblock rows 25 outward in the tire lateral direction. - The
narrow grooves 30 here each have a groove width within a range from 1 to 2 mm, both inclusive, and a groove depth within a range from 1 to 15 mm, both inclusive, and include a sipe. Here, “sipe” refers to a groove formed into a narrow shape in thetread surface 3. When thepneumatic tire 1 is mounted on a regular rim, inflated to a regular internal pressure, and placed under no load conditions, wall surfaces constituting the sipe do not come into contact with each other. When the sipe is positioned in a portion of a ground contact surface formed on a flat plate with a load applied in a vertical direction on the plate, or when theblock 20 where the sipe is formed collapses, the wall surfaces constituting the sipe, or at least portions of areas disposed on the wall surfaces, come into contact with each other as a result of deformation of theblock 20. Here, “regular rim” refers to a “standard rim” defined by the Japan Automobile Tyre Manufacturers Association Inc. (JATMA), a “design rim” defined by the Tire and Rim Association, Inc. (TRA), or a “measuring rim” defined by the European Tyre and Rim Technical Organisation (ETRTO). “Regular internal pressure” refers to “maximum air pressure” defined by JATMA, a maximum value given in “Tire Load Limits at Various Cold Inflation Pressures” defined by TRA, or “Inflation Pressures” defined by ETRTO. Thenarrow grooves 30 in the present embodiment, even when positioned on the ground contact surface, maintain a state in which the groove walls are separated from each other, and include such a sipe. -
FIG. 2 is a detailed view of part A ofFIG. 1 . Thelug grooves 15 that define both sides of theblock 20 in the tire circumferential direction incline in a direction toward the trailing side in the tire rotation direction, as it goes from the tire equator line CL side toward the outer side in the tire lateral direction, and thus an end portion on the tire equator line CL side in the tire lateral direction of theblock 20 is positioned on a frontmost side in the tire rotation direction at anedge portion 21 on the leading side in the tire rotation direction. Further, at theedge portion 21 on the trailing side of theblock 20 in the tire rotation direction, an end portion on the outer side in the tire lateral direction is positioned on the backmost side in the tire rotation direction. - Further, in the
blocks 20 constituting the fourblock rows 25 other than the twoblock rows 25 positioned on both end sides in the tire lateral direction, thenarrow grooves 30 include a lateralnarrow groove 31 extending in the tire lateral direction, and circumferentialnarrow grooves 32 extending in the tire circumferential direction. The lateralnarrow groove 31 of thenarrow grooves 30 has at least one end that opens to the circumferentialmain grooves 10 defining theblock 20. Further, the circumferentialnarrow grooves 32 have at least one end that opens to thelug grooves 15 defining theblock 20. - Specifically, the lateral
narrow groove 31 extending in the tire lateral direction is configured so that one end opens to the circumferentialmain groove 10 that defines the tire lateral direction CL side of theblock 20 in the tire lateral direction, and another end opens to the circumferentialmain groove 10 that defines the outer side of theblock 20 in the tire lateral direction. Both ends of the lateralnarrow groove 31 thus form openingportions 34 that respectively open to the circumferentialmain grooves 10. - Further, the lateral
narrow groove 31 bends at two locations while extending in the tire lateral direction, and includes twobent portions 35. The twobent portions 35 bend in directions such that the portion of the lateralnarrow groove 31 positioned outward from thebent portion 35 in the tire lateral direction is positioned further to the trailing side in the tire rotation direction than the portion of the lateralnarrow groove 31 positioned inward from thebent portion 35 in the tire lateral direction. These twobent portions 35 are positioned in a central region of theblock 20 in the tire lateral direction at different positions in the tire circumferential direction, and the portion of the lateralnarrow groove 31 between thebent portions 35 extends in the tire circumferential direction at a short length. In other words, the lateralnarrow groove 31 bends at the twobent portions 35, forming a so-called crank-like shape. - Further, two of the circumferential
narrow grooves 32 are provided, and these two circumferentialnarrow grooves 32 are positioned further outward of theblock 20 in the tire lateral direction than thebent portions 35 of the lateralnarrow groove 31. That is, one circumferentialnarrow groove 32, of the two circumferentialnarrow grooves 32, is positioned inward from thebent portions 35 in the tire lateral direction, and the other circumferentialnarrow groove 32 is positioned outward from thebent portions 35 in the tire lateral direction. The circumferentialnarrow groove 32, of the two circumferentialnarrow groove 32, positioned inward from thebent portions 35 in the tire lateral direction is positioned on the leading side of the lateralnarrow groove 31 in the tire rotation direction, and the circumferentialnarrow groove 32 positioned outward from thebent portions 35 in the tire lateral direction is positioned on the trailing side of the lateralnarrow groove 31 in the tire rotation direction. - The circumferential
narrow grooves 32, at these positions, are each configured so that one end opens to thelug groove 15, and the other end intersects the lateralnarrow groove 31, connecting and opening to the lateralnarrow groove 31. Specifically, the circumferentialnarrow groove 32 positioned inward from thebent portions 35 in the tire lateral direction is configured so that an end portion on the leading side in the tire rotation direction is an openingportion 34 that opens to thelug groove 15, and an end portion on the trailing side in the tire rotation direction is connected to the lateralnarrow groove 31. Further, the circumferentialnarrow groove 32 positioned outward from thebent portions 35 in the tire lateral direction is configured so that an end portion on the trailing side in the tire rotation direction is an openingportion 34 that opens to thelug groove 15, and an end portion on the leading side in the tire rotation direction is connected to the lateralnarrow groove 31. - A portion where the circumferential
narrow groove 32 and the lateralnarrow groove 31 intersect form anintersection point 37, and thenarrow grooves 30 include two intersection points 37 formed by the two circumferentialnarrow grooves 32 intersecting one lateralnarrow groove 31. That is, thenarrow grooves 30 configured to include twointersection points 37 by two circumferentialnarrow grooves 32 being provided as one of thenarrow grooves 30, and the two circumferentialnarrow grooves 32 intersecting the lateralnarrow groove 31, which is anothernarrow groove 30. Thebent portions 35 of the lateralnarrow groove 31 are positioned between the twointersection points 37 in the tire lateral direction. - Further, the
narrow grooves 30 are configured so that a distance W3 in the tire lateral direction between one of the two openingportions 34 that open to thelug groove 15 and, among both ends of theblock 20 in the tire lateral direction, the end portion near the openingportion 34 is within a range of 0.15≤(W3/WB)≤0.40 with respect to a width WB of theblock 20 in the tire lateral direction. Specifically, the distance W3 in the tire lateral direction between the openingportion 34 of, among the two circumferentialnarrow grooves 32, the circumferentialnarrow groove 32 positioned on the leading side in the tire rotation direction, and the end portion of theblock 20 in the tire lateral direction near the openingportion 34 is within the range of 0.15≤(W3/WB)≤0.40 with respect to the width WB of theblock 20. - Similarly, a distance W4 in the tire lateral direction between the other of the two opening
portions 34 of thenarrow groove 30 that open to thelug groove 15 and, among both ends of theblock 20 in the tire lateral direction, the end portion near the openingportion 34 is within a range of 0.15≤(W4/WB)≤0.40 with respect to the width WB of theblock 20 in the tire lateral direction. In other words, the distance W4 in the tire lateral direction between the openingportion 34 of, among the two circumferentialnarrow grooves 32, the circumferentialnarrow groove 32 positioned on the trailing side in the tire rotation direction, and the end portion of theblock 20 in the tire lateral direction near the openingportion 34 is within the range of 0.15≤(W4/WB)≤0.40 with respect to the width WB of theblock 20 in the tire lateral direction. - Note that the positions of the opening
portions 34 in the distances W3, W4 are the center in the opening width of the openingportions 34 in the tire lateral direction. Further, preferably the distance W3 and the distance W4 are about the same. - Further, the
narrow grooves 30 are configured so that a bend angle α1 of thenarrow groove 30 at one of the twobent portions 35 and a bend angle α2 of thenarrow groove 30 at the otherbent portion 35 are within ranges of 90°≤α1≤120° and 90°≤α2≤120°, respectively. For example, of the twobent portions 35 of thenarrow groove 30, when α1 is defined as the bend angle of thebent portion 35 positioned on the trailing side in the tire rotation direction, the bend angle α1 is within the range of 90°≤α1≤120°. Similarly, of the twobent portions 35, when α2 is defined as the bend angle of thebent portion 35 positioned on the leading side in the tire rotation direction, the bend angle α2 is within the range of 90°≤α2≤120°. Note that the bend angles α1, α2 in this case are both minor angles of thebent portions 35. - Further, the
narrow grooves 30 are configured so that a bend angle β1 between thenarrow grooves 30 at one of the twointersection points 37 and a bend angle β2 between thenarrow grooves 30 at theother intersection point 37 are within ranges of 70°≤β1≤90° and 70°≤β2≤90°, respectively. For example, angle β1 between the circumferentialnarrow groove 32 and the lateralnarrow groove 31 that intersect at theintersection point 37 of the twointersection points 37 positioned outward in the tire lateral direction is within the range of 70°≤β1≤90°. Similarly, angle β2 between the circumferentialnarrow groove 32 and the lateralnarrow groove 31 that intersect at theintersection point 37 of the twointersection points 37 positioned inward in the tire lateral direction is within the range of 70°≤β2≤90°. Note that when the angles β1, β2 of thenarrow grooves 30 in this case are other than 90°, the angles β1, β2 become relative angles on the acute angle side of the circumferentialnarrow groove 32 and the lateralnarrow groove 31 that intersect at theintersection point 37. -
FIG. 3 is a cross-sectional view taken along B-B ofFIG. 2 . Thenarrow grooves 30 have a groove depth d1 within a range of 0.05≤(d1/d2)≤0.50 with respect to a groove depth d2 of the circumferentialmain groove 10. Further, thenarrow grooves 30 each have two or more groove depths and, in the present embodiment, the groove depths differ in the lateralnarrow groove 31 and the circumferentialnarrow groove 32 of thenarrow grooves 30. Specifically, a groove depth d4 of the lateralnarrow groove 31 is greater than a groove depth d3 of the circumferentialnarrow groove 32, and the relationship between the groove depth d3 of the circumferentialnarrow groove 32 and the groove depth d4 of the lateralnarrow groove 31 is within a range of 0.5≤(d3/d4)≤0.8. - The
block 20 is defined into three or moresmall blocks 40 by thenarrow grooves 30. That is, the lateralnarrow groove 31 and the circumferentialnarrow grooves 32 of thenarrow grooves 30 are connected to the circumferentialmain grooves 10 and thelug grooves 15, and the lateralnarrow groove 31 and the circumferentialnarrow grooves 32 are connected to each other. Thus, theblocks 20 are divided into a plurality of regions in a plan view by thenarrow grooves 30, each region being asmall block 40. According to the present embodiment, foursmall blocks 40 are formed in each of theblocks 20. That is, theblocks 20 are each separated in the tire circumferential direction by the lateralnarrow grooves 31, and each of the regions separated in the tire circumferential direction are further separated in the tire lateral direction by the circumferentialnarrow grooves 32, thereby defining theblock 20 into four of the small blocks 40. - In the
blocks 20 of the four of the sixblock rows 25 other than the twoblock rows 25 positioned on both end sides in the tire lateral direction, thenarrow grooves 30 are formed in the form described above, defining each of theblocks 20 into four of the small blocks 40. Further, in theblocks 20 of the two of the sixblock rows 25 positioned on both end sides in the tire lateral direction, only the lateralnarrow groove 31 is formed as thenarrow groove 30 and not the circumferentialnarrow groove 32. - The
pneumatic tire 1 according to the present embodiment thus configured is applied to a heavy duty pneumatic tire. When mounted on a vehicle, thepneumatic tire 1 is mounted on a rim wheel and then mounted with the rim on the vehicle in an inflated state. Thepneumatic tire 1 mounted on the rim wheel is mounted on a large vehicle such as a truck or a bus, for example. - When a vehicle with the
pneumatic tire 1 mounted thereon runs, thepneumatic tire 1 rotates while thetread surface 3 of thetread surface 3 located at the bottom contacts the road surface. When a vehicle with thepneumatic tire 1 mounted thereon run on dry road surfaces, the vehicle mainly run by a friction force between thetread surface 3 and the road surface. This friction force transmits a driving force and a braking force to the road surface and generates a swivel force. Further, when the vehicle runs on wet road surfaces, the vehicle runs while water between thetread surface 3 and the road surface enters the circumferentialmain grooves 10, thelug grooves 15, and the like, and is discharged by these grooves. In this way, thetread surface 3 readily contacts the road surface, allowing the vehicle to run by the friction force between thetread surface 3 and the road surface. - Further, when the vehicle run on icy and snowy road surfaces, the edges serving as boundary portions between the
tread surface 3 and the grooves get caught on the icy and snowy road surfaces, making it possible to produce resistance between thetread surface 3 and the icy and snowy road surfaces and generate traction. Additionally, in thepneumatic tire 1 according to the present embodiment, thenarrow grooves 30 are formed in theblocks 20. Accordingly, the number of edge components of each of theblocks 20 increases and the number of edge components of thetread surface 3 in its entirety increases, making it possible to ensure traction performance as well as performance on snow and ice during running on icy and snowy road surfaces. Further, thenarrow groove 30 formed in theblock 20 includes twobent portions 35 and two intersection points 37. As a result, thenarrow groove 30 can maintain sufficient edge components and the edge effect can be exhibited in various directions, making it possible to improve performance on snow and ice. - Further, when the
pneumatic tire 1 rotates, a hitting sound is generated when theblocks 20 contact the road surface and this hitting sound expands to the periphery, producing noise. However, thebent portions 35 are formed in thenarrow grooves 30 formed in theblocks 20, and thus the air compressed by sound readily accumulates in thenarrow grooves 30. Further, the intersection points 37 are formed in thenarrow groove 30, and the circumferentialnarrow grooves 32 and the lateralnarrow groove 31 intersect at the intersection points 37, and thus the compressed air that flows in thenarrow grooves 30 is readily dispersed by the intersection points 37. Thus, the compressed air that flows through thenarrow grooves 30 does not readily flow to the circumferentialmain grooves 10, reducing the amount of sound that flows outside the contact patch. As a result, it is possible to improve performance on snow and ice and reduce noise in a compatible manner. - Further, the
bent portions 35 of thenarrow groove 30 are each positioned between the intersection points 37 in the tire lateral direction and thus, even when a portion of the compressed air that flows through thenarrow groove 30 passes through thebent portions 35, the air can be dispersed at the positions of the intersection points 37, making it possible to more reliably decrease the likelihood that the compressed air that flows through thenarrow groove 30 will flow in the direction of the circumferentialmain grooves 10. Further, the circumferentialnarrow grooves 32 of thenarrow grooves 30 open to thelug grooves 15, and the lateralnarrow groove 31 opens to the circumferentialnarrow grooves 10, and thus thenarrow grooves 30 readily open and close in a groove width direction. Thus, even when snow enters thenarrow grooves 30, thenarrow grooves 30 open in the groove width direction, making it possible to discharge snow and maintain performance on snow. Further, thenarrow grooves 30 open to thelug grooves 15 and the circumferentialmain grooves 10, allowing the water in thenarrow grooves 30 to be readily discharged to thelug grooves 15 and the circumferentialmain grooves 10 sides, making it possible to maintain performance on ice. As a result, it is possible to more reliably improve performance on snow and ice and reduce noise in a compatible manner. - Further, the distances W3, W4 in the tire lateral direction between the opening
portions 34 of the circumferentialnarrow grooves 32 and the end portions of theblock 20 in the tire lateral direction are within the ranges of 0.15≤(W3/WB)≤0.40 and 0.15≤(W4/WB)≤0.40, making it possible to suppress block breakage and improve performance on snow and ice. That is, when the relationships between the distances W3, W4 and the width WB of theblock 20 are (W3/WB)<0.15 and (W4/WB)<0.15, the openingportion 34 of the circumferentialnarrow groove 32 is too close to the end portion of theblock 20, potentially increasing likelihood of block breakage generation. Further, when the relationships between the distances W3, W4 and the width WB of theblock 20 are (W3/WB)>0.40 and (W4/WB)>0.40, theintersection point 37 and thebent portion 35 are too close to each other, making it less likely to exhibit independent edge effects by the intersection points 37 and thebent portions 35, and potentially less likely to achieve sufficient performance on snow and ice. In contrast, when the relationships between the distances W3, W4 and the width WB of theblock 20 is within the ranges of 0.15≤(W3/WB)≤0.40 and 0.15≤(W4/WB)≤0.40, the distance between the openingportion 34 of the circumferentialnarrow groove 32 and the end portion of theblock 20, and the distance between theintersection point 37 and thebent portion 35 can each be appropriately set. As a result, performance on snow and ice can be more reliably improved while suppressing block breakage. - Further, the groove depth d1 of the
narrow groove 30 is within the range of 0.05≤(d1/d2)≤0.50 with respect to the groove depth d2 of the circumferentialmain groove 10, making it possible to improve performance on snow and ice while suppressing noise caused by thenarrow groove 30. In other words, when the relationship between the groove depth d1 of thenarrow groove 30 and the groove depth d2 of the circumferentialmain groove 10 is (d1/d2)<0.05, the groove depth d1 of thenarrow groove 30 is too small, potentially making it difficult to sufficiently achieve the effect of improving performance on snow and ice by thenarrow groove 30. Further, when the relationship between the groove depth d1 of thenarrow groove 30 and the groove depth d2 of the circumferentialmain groove 10 is (d1/d2)>0.50, the groove depth d1 of thenarrow groove 30 is too large, potentially increasing the noise when the positions where thenarrow grooves 30 are formed contact the ground. In contrast, when the relationship between the groove depth d1 of thenarrow groove 30 and the groove depth d2 of the circumferentialmain groove 10 is within the range of 0.05≤(d1/d2)≤0.50, it is possible to more reliably exhibit the effect of improving performance on snow and ice while suppressing noise caused by thenarrow groove 30. As a result, it is possible to more reliably improve performance on snow and ice and reduce noise in a compatible manner. - Further, the
narrow grooves 30 are configured so that the relationship between the groove depth d3 of the circumferentialnarrow groove 32 and the groove depth d4 of the lateralnarrow groove 31 is within the range of 0.5≤(d3/d4)≤0.8, making it possible to suppress noise while suppressing the generation of cracks. That is, when the relationship between the groove depth d3 of the circumferentialnarrow groove 32 and the groove depth d4 of the lateralnarrow groove 31 is (d3/d4)<0.5, the difference between the groove depth d3 of the circumferentialnarrow groove 32 and the groove depth d4 of the lateralnarrow groove 31 is too large, increasing the likelihood of stress concentration when a load acts on theblocks 20 and potentially generating cracks from thenarrow grooves 30. Further, when the relationship between the groove depth d3 of the circumferentialnarrow groove 32 and the groove depth d4 of the lateralnarrow groove 31 is (d3/d4)>0.8, the groove depth d3 of the circumferentialnarrow groove 32 is too large, potentially increasing the noise when the positions where the circumferentialnarrow grooves 32 are formed contact the ground. In contrast, when the relationship between the groove depth d3 of the circumferentialnarrow groove 32 and the groove depth d4 of the lateralnarrow groove 31 is within the range of 0.5≤(d3/d4)≤0.8, it is possible to suppress the generation of cracks and suppress noise caused by the circumferentialnarrow grooves 32. As a result, it is possible to more reliably reduce noise while suppressing crack generation. - Further, the two angles β1, β2 between the lateral
narrow groove 31 and the circumferentialnarrow grooves 32 intersecting at the twointersection points 37 are within the ranges of 70°≤β1≤90° and 70°≤β2≤90°, respectively, making it possible to exhibit the edge effect in a greater number of directions and increase performance on snow and ice. In other words, when the angles β1, β2 are β1≤70° and β2≤70°, the relative angles between the intersecting lateralnarrow groove 31 and the circumferentialnarrow grooves 32 are too small, restricting the directions in which the edge effect is exhibited and potentially decreasing the likelihood that performance on snow and ice will be sufficiently exhibited. In contrast, when the two angles β1, β2 between the lateralnarrow groove 31 and the circumferentialnarrow grooves 32 intersecting at the twointersection points 37 are within the ranges of 70°≤β1≤90° and 70°≤β2≤90°, it is possible to exhibit the edge effect in a greater number of directions. As a result, performance on snow and ice can be more reliably improved. - Further, the
narrow groove 30 are configured so that the bend angles α1, α2 of the twobent portions 35 are within the ranges of 90°≤α1≤120° and 90°≤α2≤120°, respectively, making it possible to more reliably improve performance on snow and ice by the edge effect while reducing noise. That is, when the bend angles α1, α2 of thebent portions 35 are α1≤90° and α2≤90°, the portions on both sides of thenarrow groove 30 that sandwich thebent portion 35 are close to each other, making it difficult to exhibit the independent edge effects by the respective portions and potentially decreasing the likelihood of effectively improving performance on snow and ice. Further, when the bend angles α1, α2 of thebent portions 35 are α1>120° and α2>120°, compressed air more readily flows into thenarrow groove 30 and thus into the circumferentialmain grooves 10, potentially decreasing the likelihood of noise reduction. In contrast, when the bend angles α1, α2 of thebent portions 35 are within the ranges of 90°≤α1≤120° and 90°≤α2≤120°, it is possible to exhibit the edge effect independently by the portions on both sides of thenarrow groove 30 that sandwich thebent portion 35 while more reliably suppressing the flow of compressed air through thenarrow groove 30 and into the circumferentialmain grooves 10. As a result, it is possible to more reliably improve performance on snow and ice and reduce noise in a compatible manner. - Further, the
narrow grooves 30 are formed in theblocks 20 of the plurality ofblock rows 25, making it possible to more reliably increase the edge components of thetread surface 3. As a result, performance on snow and ice can be more reliably improved. - Further, the
narrow grooves 30 are formed in theblocks 20 of the fourblock rows 25 other than the twoblock rows 25 positioned on both end sides in the tire lateral direction, making it possible to decrease the likelihood that the air compressed in thenarrow grooves 30 will flow to the circumferentialmain groove 10 side while maintaining sufficient edge components in a wider range of thetread surface 3. As a result, it is possible to more reliably improve performance on snow and ice and reduce noise in a compatible manner. - Further, the
bent portions 35 bend such that the portion of thenarrow groove 30 positioned outward from thebent portion 35 in the tire lateral direction is configured to bend further in directions positioned on the trailing side in the tire rotation direction than the portion of thenarrow groove 30 positioned inward from thebent portion 35 in the tire lateral direction, thereby making it possible to decrease the surface area of the portion that initially contacts the ground at the time of ground contact by theblock 20 and readily increases in ground contact pressure. That is, when thetread surface 3 contacts the road surface, a ground contact pressure in a central region in the tire lateral direction of the ground contact region increases. As a result, a loud hitting sound is readily produced when the region on the tire equator line CL side in the tire lateral direction contacts the ground during ground contact by each of theblocks 20. Further, in thepneumatic tire 1 according to the present embodiment, the portion of thenarrow groove 30 positioned inward from thebent portion 35 in the tire lateral direction is positioned on the leading side in the tire rotation direction than the portion of thenarrow groove 30 positioned outward from thebent portion 35 in the tire lateral direction, thereby making it possible to decrease the surface area of the portion that initially contacts the ground at the time of ground contact by theblock 20 and readily increases in ground contact pressure. As a result, the hitting sound at the time of ground contact by theblocks 20 can be reduced, and thus noise can be more reliably reduced. - Note that, while in the
pneumatic tire 1 according to the embodiment described above, thenarrow grooves 30 are configured so that thebent portions 35 are positioned between the intersection points 37, thenarrow grooves 30 may be formed in a form other than this.FIG. 4 is a modified example of the pneumatic tire according to an embodiment, and is an explanatory diagram of a case where the bent portions are positioned outward of the intersection points. Thenarrow grooves 30, for example, may be configured so that twointersection points 37 are formed between twobent portions 35, as illustrated inFIG. 4 . As long as a plurality of thebent portions 35 of thenarrow grooves 30 and a plurality of the intersection points 37 are formed, thenarrow grooves 30 may be formed in a form other than that illustrated in the embodiment described above, and the relative positional relationship between thebent portions 35 and the intersection points 37 is not limited. - Further, while in the
pneumatic tire 1 according to the embodiment described above thebent portions 35 are formed in the lateralnarrow groove 31, thebent portions 35 may be formed in an area other than the lateralnarrow groove 31.FIG. 5 is a modified example of the pneumatic tire according to an embodiment, and is an explanatory diagram of a case where the bent portions are formed in the circumferential narrow grooves. Thebent portions 35 of thenarrow grooves 30, for example, may be formed in the circumferentialnarrow groove 32, and the lateralnarrow grooves 31 may be connected to the circumferentialnarrow groove 32, as illustrated inFIG. 5 . Thus, thebent portions 35 may be formed in the circumferentialnarrow groove 32, and may be formed in both the circumferentialnarrow groove 32 and the lateralnarrow groove 31. - Further, while in the
pneumatic tire 1 according to the embodiment described above thenarrow grooves 30 are configured so that the groove depth of the lateralnarrow groove 31 is greater than the groove depth of the circumferentialnarrow groove 32, the groove depth of the circumferentialnarrow groove 32 may be greater than the groove depth of the lateralnarrow groove 31. Further, the groove depth of thenarrow groove 30 may differ for each of theblocks 20, and may be formed at three or more depths within each of theblocks 20. Further, thenarrow grooves 30 may be configured so that, for example, the lateralnarrow groove 31 is a regular groove in which the groove walls are continuously spaced apart even when theblock 20 contacts the ground, and the circumferentialnarrow groove 32 may be formed by a sipe or the like, resulting in a mixture of regular groove and sipes. -
FIGS. 6A to 6F are tables listing the results of performance tests of pneumatic tires. In relation to thepneumatic tire 1 described above, performance evaluation tests conducted on a pneumatic tire of a conventional example and thepneumatic tires 1 according to embodiments of the present technology will be described below. The performance evaluations tests were conducted on performance on snow and ice, which is traction performance when driving on icy and snowy road surfaces, pass-by noise which is noise produced as thepneumatic tire 1 rolls, and cracks or block breakage from thenarrow groove 30 indicating failure of theblock 20. - The performance evaluation tests were conducted by mounting the
pneumatic tire 1 having a size of 315/70R22.5 defined by ETRTO on a regular rim, adjusting the air pressure to 900 kPa, mounting the tire onto a 2-D test vehicle, and then running tests. Each test item for performance on snow and ice was evaluated by having panelists run the test vehicle with thepneumatic tire 1 to be evaluated mounted thereon, and conducting a feeling evaluation when driving the test vehicle on a test course that included snow-covered and icy road surfaces. Performance on snow and ice is expressed by using the evaluation result of Conventional Example described later as an index value of 100. A larger index value indicates a greater degree of excellence in performance on snow and ice. Further, pass-by noise was evaluated on the basis of the measured volume of exterior pass-by noise in accordance with a tire noise test method defined in ECE (Economic Commission for Europe) Regulation No. 117 Revision 2 (ECE R117-02). In this test, the test vehicle run from an area at a sufficient distance in front of a noise measurement section, the engine was stopped immediately in front of the section, and a maximum noise level dB (noise level within a frequency range of from 800 to 1200 Hz) in the noise measurement section during coasting was measured at a plurality of speeds obtained by substantially equally dividing a speed range into eight or more intervals of ±10 km/h with respect to a standard speed, and setting the average as the exterior pass-by noise. The maximum noise level dB is a sound pressure dB (A) measured through an A-characteristic frequency correction circuit using a stationary microphone installed 7.5 m laterally from a running center line at an intermediate point in the noise measurement section and at a height of 1.2 m from the road surface. Further, cracks and block breakage from thenarrow groove 30 was evaluated based on the generation of cracks and block breakage from thenarrow groove 30 after driving 50000 km with a market monitor, and expressed by using the evaluation result of Conventional Example described later as an index value of 100. A larger index value indicates less cracks and block breakage. - Performance evaluation tests were conducted on 34 pneumatic tires, namely a pneumatic tire of Conventional Example, which is one example of the
pneumatic tire 1 in the related art, and Examples 1 to 33 which are thepneumatic tires 1 according to the present technology. Among thesepneumatic tires 1, in the pneumatic tire of Conventional Example, thenarrow grooves 30 including thebent portions 35 are formed in theblocks 20, but do not include the intersection points 37. - In contrast, in Examples 1 to 33, which are examples of the
pneumatic tire 1 according to the present technology, thenarrow grooves 30 each including twobent portions 35 and twointersection points 37 are formed in theblocks 20. Further, in thepneumatic tires 1 according to Examples 1 to 33, whether thenarrow groove 30 opens to the circumferentialmain groove 10, the position of the openingportion 34 of thenarrow groove 30 with respect to the width of theblock 20, the groove depth d1 of thenarrow groove 30 with respect to the groove depth d2 of the circumferentialmain groove 10, the groove depth d3 of the circumferentialnarrow groove 32 with respect to the groove depth d4 of the lateralnarrow groove 31, the angles β1, β2 between thenarrow grooves 30 at theintersection point 37, the bend angles α1, α2 of thebent portions 35, the number ofblock rows 25 in which thenarrow groove 30 is disposed, and the absence or presence of rotation directionality of thepneumatic tire 1 are each different. - As shown in
FIGS. 6A to 6F , the results of the evaluation tests conducted using thesepneumatic tires 1 indicate that thepneumatic tires 1 of Examples 1 to 33 can improve both performance on snow and ice and pass-by noise in comparison with Conventional Example, and can also suppress cracks and block breakage from thenarrow groove 30 to the same degree as in Conventional Example. In other words, thepneumatic tires 1 according to Examples 1 to 33 achieve the effect of improving performance on snow and ice and reducing noise in a compatible manner.
Claims (18)
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JP2016170230A JP6319384B2 (en) | 2016-08-31 | 2016-08-31 | Pneumatic tire |
JP2016-170230 | 2016-08-31 | ||
PCT/JP2017/031127 WO2018043553A1 (en) | 2016-08-31 | 2017-08-30 | Pneumatic tire |
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Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20210086563A1 (en) * | 2017-07-27 | 2021-03-25 | The Yokohama Rubber Co., Ltd. | Pneumatic Tire |
US11235621B2 (en) * | 2016-08-31 | 2022-02-01 | The Yokohama Rubber Co., Ltd. | Pneumatic tire |
US11312181B2 (en) * | 2016-08-31 | 2022-04-26 | The Yokohama Rubber Co., Ltd. | Pneumatic tire |
EP4299339A1 (en) * | 2022-07-01 | 2024-01-03 | Sumitomo Rubber Industries, Ltd. | Heavy-duty tire |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2023000676A (en) * | 2021-06-18 | 2023-01-04 | 株式会社ブリヂストン | tire |
JP2023000674A (en) * | 2021-06-18 | 2023-01-04 | 株式会社ブリヂストン | tire |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0390317A (en) * | 1989-08-31 | 1991-04-16 | Ohtsu Tire & Rubber Co Ltd :The | Sipe forming member for forming block tire with sipe |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5179612A (en) | 1975-01-07 | 1976-07-12 | Hitachi Cable | JIKUKEYO ARUMINIUMUGOKIN |
JPS5530059U (en) | 1978-08-16 | 1980-02-27 | ||
DE3329320A1 (en) * | 1983-08-13 | 1985-02-28 | Uniroyal Englebert Reifen GmbH, 5100 Aachen | Pneumatic vehicle tyre |
JPS62292508A (en) * | 1986-06-12 | 1987-12-19 | Yokohama Rubber Co Ltd:The | Tire for snow-icy road |
JP2672061B2 (en) * | 1992-12-11 | 1997-11-05 | 住友ゴム工業株式会社 | Pneumatic tire |
GB9814102D0 (en) | 1998-06-30 | 1998-08-26 | Sumitomo Rubber Ind | Improvements to tyres |
JP2000247112A (en) * | 1999-02-25 | 2000-09-12 | Bridgestone Corp | Pneumatic tire |
JP2005153812A (en) * | 2003-11-28 | 2005-06-16 | Bridgestone Corp | Pneumatic tire |
JP4262650B2 (en) | 2004-08-11 | 2009-05-13 | 東洋ゴム工業株式会社 | Pneumatic tire |
JP4658579B2 (en) * | 2004-12-09 | 2011-03-23 | 株式会社ブリヂストン | Pneumatic tire |
JP4537952B2 (en) * | 2005-12-27 | 2010-09-08 | 住友ゴム工業株式会社 | Pneumatic tire |
JP5530059B2 (en) | 2007-10-30 | 2014-06-25 | 株式会社ブリヂストン | Pneumatic tire |
JP4957786B2 (en) | 2009-02-12 | 2012-06-20 | 横浜ゴム株式会社 | Pneumatic tire |
JP4825288B2 (en) * | 2009-08-24 | 2011-11-30 | 住友ゴム工業株式会社 | Pneumatic tire |
JP5227355B2 (en) * | 2010-03-19 | 2013-07-03 | 住友ゴム工業株式会社 | Heavy duty tire |
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JP6304329B2 (en) * | 2016-08-31 | 2018-04-04 | 横浜ゴム株式会社 | Pneumatic tire |
JP6299823B2 (en) * | 2016-08-31 | 2018-03-28 | 横浜ゴム株式会社 | Pneumatic tire |
JP6319385B2 (en) * | 2016-08-31 | 2018-05-09 | 横浜ゴム株式会社 | Pneumatic tire |
-
2016
- 2016-08-31 JP JP2016170230A patent/JP6319384B2/en active Active
-
2017
- 2017-08-30 US US16/091,506 patent/US11718129B2/en active Active
- 2017-08-30 EP EP17846557.1A patent/EP3508356B1/en active Active
- 2017-08-30 WO PCT/JP2017/031127 patent/WO2018043553A1/en unknown
- 2017-08-30 CN CN201780021875.1A patent/CN109070646B/en not_active Expired - Fee Related
- 2017-08-30 RU RU2018134177A patent/RU2705438C1/en active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0390317A (en) * | 1989-08-31 | 1991-04-16 | Ohtsu Tire & Rubber Co Ltd :The | Sipe forming member for forming block tire with sipe |
Non-Patent Citations (1)
Title |
---|
machine translation for Japan 03-090317 (Year: 2022) * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
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US11235621B2 (en) * | 2016-08-31 | 2022-02-01 | The Yokohama Rubber Co., Ltd. | Pneumatic tire |
US11312181B2 (en) * | 2016-08-31 | 2022-04-26 | The Yokohama Rubber Co., Ltd. | Pneumatic tire |
US20210086563A1 (en) * | 2017-07-27 | 2021-03-25 | The Yokohama Rubber Co., Ltd. | Pneumatic Tire |
US11932057B2 (en) * | 2017-07-27 | 2024-03-19 | The Yokohama Rubber Co., Ltd. | Pneumatic tire |
EP4299339A1 (en) * | 2022-07-01 | 2024-01-03 | Sumitomo Rubber Industries, Ltd. | Heavy-duty tire |
Also Published As
Publication number | Publication date |
---|---|
EP3508356A4 (en) | 2020-03-25 |
WO2018043553A1 (en) | 2018-03-08 |
JP2018034692A (en) | 2018-03-08 |
US11718129B2 (en) | 2023-08-08 |
EP3508356B1 (en) | 2021-03-31 |
CN109070646A (en) | 2018-12-21 |
JP6319384B2 (en) | 2018-05-09 |
EP3508356A1 (en) | 2019-07-10 |
RU2705438C1 (en) | 2019-11-07 |
CN109070646B (en) | 2020-10-09 |
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